Valve mechanism for engines.



2 SHEBTBSHEET l PATENTED FEB. 28, 1905.

C. D. STEVENS.

VALVE MECHANISM FOR ENGINES.

APPLICATION IILBD OUT. 19. 1904.

IIE.

om M43137. a a

No. 783,709. I PATBNTBD FEB. 28, 1905.

0. D. STEVENS.

VALVE MECHANISM FOR ENGINES.

APPLIGATION FILED 00119. 1904.

2 SHEETS-SHEET 2.

ttl'o. 788,709.

ltliviirnn Patented February 28, 1905..

l EMT irrica CHARLES l). STEVENS, OF NEW YORK. Y., ASSIGNOR TO MARSHALL T. DAVIDSON, OF BROOKLYN, NEW YORK.

VALVE WlECl UMNllSWI FOR ENtalNlESu SPECIFICATION forming part of Letters Patent No. 783,709, dated February 28, 1905.

Application filed October 19, 1904:. Serial Ne-v 229,052.

1'0 (tZZ Iv/tent [it vita/y concern:

Be it known that .l, CHARLES l). S'rnvnNs, a citizen of the United States, and a resident of the borough of Brooklyn, in the city and State of New York, have invented a new and useful Improvement in Valve lllechanism for Engines, of which the following is a specification.

in has been found Where a compound directacting engine is used in connection with a pump that in the present practice of admitting the full pressure of the motive power exhaust from a high-pressure cylinder to a lowpressure cylinder when the piston in the lowpressure cylinder is at the limit of its move ment in either direction a noisy closure of the pump-valves is caused, due to the high initial velocity imparted to the pistons.

The object of this present invention is to provide mechanism for eliminating this noise and consequent jar to a very considerable ex tent.

The invention contemplates the use of a valve controlled by the movement of the pistons, which valve is so arranged as to admit a slight amount of the exhaust motive fluid to a lowpressure cylinder when the piston therein is at the limit of its stroke in either direction, the valve gradually increasing the amount of the motive iiuid as the piston moves away from its said limits of movement.

A practical embodiment of my invention is represented in the accompanying drawii'igs, in which--- l igure 1 represents in side elevation a compound pump with my invention applied thereto. Fig. 2 is an end view 01 the same, and .liig. 3 is a detail vertical central section taken longitudinally through the engine-cylinders and their 'val\'e-chests.

in the accompanying drawings 1 have represented a compound direct-acting engine and pump. The pump itself is denoted by 1.

The engine herein shown is of the two-cylinder type, the primary or high-pressure cylinder being denoted by 2 and the secondary or low-pressure cylinder by 3. The valvechests ot' the cylinders 2 and 3 are denoted by at and 5. The valves 6 and 7 are connected to work simultaneously by the usual rod 8. The

piston 9, which works in the chamber 10 oi the primary cylinder 2, is provided with a central rod 11, and the piston 12, which works in the chamber 13 of the secondary cylinder 3, is provided with two piston-rods 14, which are connected to the piston-rod 11. at a point exterior to the cylinder 1, so as to cause the two pistons to work together. A receiver 15 is shown herein, to which a pipe to leads from the main exhaust oi the primary cylinder and from which a pipe 17 leads to the valve-chest 5 of the secondary cylinder. The cylinders and their valves are provided with the usual ports.

An auxiliary valve-box 18 is mounted on the secondary valve-chest 5 and is interposed between the pipe 17 and the said valve-chest. A rocking valve 19 is seated in the valve-box 18, and it is provided with a through-port 20, one end of which is at all times in open cornmunication with the pipe 17 and the other end of which is brought into more or less open communication with a port 21, leading from the face of the valve to the interior of the valve-chest 5.

l A two-armed rocking lever is pivoted at 22 to the side of the valve-chest t, the lower arm 23 of which lever is adjustably connected by a rod 24 to the piston-rods, so as to be opcrated by the movement of the said piston-rods.. The upper arm 25 of the said two-armed rocking lever is adjustably connected by a rod 26 to an arm 27, fixed to the stem of the valve 1%). The several adjustable connectioi'is permit 0] the valve '19 being so adjusted as to insure the proper reciprocating movement of the wtlve with relation to the movement oi the pistons. in operation when the pistons in the cylinders reach the limit of their movea'nent in one direction the valves 6 and Tare automatically thrown in the usual manner to open the main admission-port to the proper side of the primary piston and to open the port for admitting the exhaust motive iiuid from the primary cylinder to the proper side of the piston in the secondary cylinder. To prevent the full force of the motive power being admitted at once to the face of the piston in the secondary cylinder, the valve 19 has been rocked by the movement of the piston-rod to a point where only a small amount of the exhaust fluid Will be fed to the face of the secondary-cylinder piston while the piston is at the limit of its movement. As the pistons are moved away from the limit of their movement the connection between their rods and the valve 19 will rock the valve, thus gradually increasing the amount of motive fluid fed to the secondaryoylinder piston. This will materially reduce the noise of the pump and also insure a more even running thereof.

It is obvious that my invention may be applied to any form of engine wherein the exhaust from a cylinder of one pressure leads to a cylinder of lower pressure whether the number of cylinders be two or more. It is also evident that various changes might be made in the construction, form, and arrangement of the several parts Without departing from the spirit and scope of my invention. Hence I do not wish to limit myself strictly to the structure herein set forth; but

\Vhat I claim is- 1. Inacompound direct-acting engine, high and low pressure cylinders, their pistons, controlling-valves therefor and an auxiliary valve connected to the pistons for controlling the feeding of the motive fluid to the low-pressure cylinder. k

2. In a compound direct-acting engine, high and low pressure cylinders, their pistons, connected piston-rods, controlling-valves for the pistons, an auxiliary valve for controlling the feed of the motive fluid to the low-pressure cylinder and means for oscillating the auxiliary valve comprising an arm carried by the auxiliary valve, a rocking lever and connections between the piston-rods and lever and the valve-arm and lever.

3. In a compound direct-acting engine, high and low pressure cylinders, their pistons, connected piston-rods, controlling-valves for the pistons, an auxiliary valve for controlling the feeding of the motive fluid to the low-pressure cylinder and means for oscillating the auxiliary Valve comprising an arm carried by the auxiliary valve, a rocking lever and adjustable connections between the piston-rods and lever and the valve-arm and lever.

4. In a compound direct-acting engine, high and low pressure cylinders, their pistons, controlling-valves therefor, an auxiliary valve and means for oscillating the auxiliary valve to automatically move it into position to feed a limited amount of motive fluid to the lowpressure cylinder when its piston is at the limits of its movement and into position to gradually increase the supply of motive fluid as the piston moves away from its said limits of movement.

In testimony that I claim the foregoing as my invention 1 have signed my name, in presence of two witnesses, this 15th day of September, 1904.

CHAS. D. STEVENS.

Witnesses:

FREDK. HAYNES, C. S. SUNDGREN. 

